摘要：The object of research is a prefix model for calculating adding and transport signals in a parallel adder circuit with a parallel transfer method. One of the most problematic places in the prefix model is the process of generating adding and carry signals, in which the beginning of the prefix calculation is provided from the first bit of the circuit. This leads, in the end, to excessive accumulation and complications of the hardware part of the device.In the course of the research, a mathematical model is used to calculate the adding and carry signals in a parallel adder circuit based on the properties of a directed acyclic graph with two typical operations.The complexity of the logical structure of the adder of binary codes is reduced, the depth of the circuit is reduced and the total length of the connecting wires is reduced. This is due to the fact that the proposed method for calculating adding and transport signals has a number of features of the device circuit synthesis, in particular, the application of a mathematical model based on the properties of an acyclic graph is calculated for:process of sequential (for lower order devices) and parallel calculation of adding and carry signals, which, in the end, reduces the complexity of the hardware of the device and does not increase the depth of the circuit;comparison of the number of computational steps of an oriented acyclic graph with the number of transfers of one to the high-order bit in the adder circuit, which allows to determine the optimal number of computational steps for the structure of the device.Due to this, it is possible to obtain optimal values for the complexity of the structure and the depth of the adder circuit. The connection between the number of computational steps of an oriented acyclic graph and the number of transfers in the parallel adder circuit with a parallel transport method indicates the expediency of comparing the structure of the adder with the corresponding oriented acyclic graph.In comparison with similar known structures of 8-bit prefix adders, this provides an increase in the quality index of 8-bit acyclic adders, for example, by power consumption, the chip area, depending on the chosen structure, by 10–40%.
